mlab.screenshot produces an all-zero array when run under x2go

I'm currently experiencing an issue where a software package that depends upon Mayavi's _mlab.screenshot_ function is producing entirely black images when passing an array generated by _mlab.screenshot_ into SciPy's _scipy.misc.imsave_ (i.e., the array produced by _screenshot_ is filled completely with zeros; more context [here](https://mail.python.org/pipermail/neuroimaging/2016-September/001159.html)). I have a theory that this may be due to an interaction between how the remote desktop server software we use (x2go) displays images and how _mlab.screenshot_ ascertains what's in the window whose image is to be saved. I haven't been able to log into a physical console for our server to verify this, but I was able to get _mlab.screenshot_ to work as expected within a local install using an environment identical to what was on the server.

While searching through previous posts I found that [historically, Mayavi had difficulty working with nx](http://comments.gmane.org/gmane.comp.python.enthought.devel/4103), which is the protocol that x2go uses. The version of Mayavi I used was 4.4.0 in the last environment I was working with. Is there a known regression involving nx in this version or some workaround that I could use to get _screenshot_ to work?